A tiny organ in our chest cavity could be the key to regulating inflammation as we age, according to new research in mice. The thymus is nestled between our lungs and is roughly the size of a dried apricot. It helps our bodies produce pathogen-fighting immune cells called T cells, particularly in childhood. The results could one day improve cancer therapies for humans, Ito says. “Our study shows that this hormone can slow down tumor growth, improve survival and also enhance the treatment efficacy of cancer immunotherapy,” he says.